A conical candle is to be made from 250 cm3 of wax. If the candle's height is three times its diameter, what radius and height should it have, to the nearest tenth?

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm